The following abbreviations that may be found in the specification and/or the drawing figures are defined as follows:
3GPP 3rd generation partnership project
CA carrier aggregation
CoMP coordinated multi-point
C-SON centralized SON
CRS cell-specific reference signal
CSI channel state information
CSI-RS channel state information reference signal
DCI downlink control information
DL downlink
DMRS demodulation reference signal or UE-specific reference signal
eNB, eNodeB evolved node B/base station in an E-UTRAN system
E-PDCCH enhanced physical downlink control channel
E-PCFICH enhanced physical control format indicator channel
E-UTRAN evolved UTRAN (LTE)
FDD frequency division duplexed
HetNet heterogeneous network
ICIC inter-cell interference coordination
LTE long term evolution
LTE-A long term evolution advanced
MAC medium access control
NMS Network Management System
O&M operation and maintenance
PBCH physical broadcast channel
PCC primary component carrier
PCell primary cell
PDCCH physical downlink control channel
PDSCH physical downlink shared channel
PDU protocol data unit
PRB physical resource block
PSS primary synchronization signal
QoC quality of service
    RAN radio access network    RF radio frequency    RS reference signal    RRC radio resource control    RRH remote radio head    SCell secondary cell    SCC secondary component carrier    SI system information    SON self optimizing network    SS search space    SSS Secondary synchronization signal    TDD time division duplexed    TTI transmission time interval, e.g. a subframe    UE user equipment    UL uplink    UTRAN universal terrestrial radio access network    X2 interface between eNBs    X2 AP X2 application protocol
The LTE carrier aggregation enhancement work item was approved in RAN Meeting#51 and further updated in RAN Meeting#52. In RAN1#66bis, the following working assumption has been agreed for support of new carrier types: introduce at least one new carrier type in 3GPP Release-11 (bandwidth agnostic from a RAN1 point of view), with at least reduced or eliminated legacy control signaling and/or CRS.